The present invention relates to a multichannel digital television system and, in particular, aspects of a system relating to navigation between channels.
One of the advantages of digital television lies in the number of channels that are available in such systems and the flexibility that is available to the television service provider regarding what channel choices may be made available to a subscriber of the service. Other than a standard set of subscription channels, the system may also include other access controlled channels such as, for example, a pay-per-view channel enabling a subscriber to pay for a particular film, sporting event etc.
In addition, the digital television system may allow access by the viewer to a number of other interactive type services, such as text based programme guides, weather maps etc. These services may be associated with dedicated digital television channels used to carry the information. Other additional menu based services may be provided enabling a user to access certain basic information in a series of pull down menus whilst watching a broadcast programme. These services operate using so-called “pilot” information carried in the same channel as a normal audiovisual channels.
Whilst the viewer benefits from the increased choice available, the large numbers of channels and services that are available may prove distracting and, in practice, a viewer may often have difficulty managing the viewing possibilities available. In addition, existing navigation tools often fail to handle correctly the interface between the navigator and access controlled channels, some of which may not be available to a particular user.
It is an object of the present invention in its broadest and/or specific aspects to overcome some or all of these problems and to facilitate the navigation of the channels by a user whilst respecting access control restrictions.